I get you sometimes for me it happens every other game/duel I play and after a certain point it just gets really annoying. Most times now if I win I'll quickly type "gg" and do /hub before they can say anything

I take it as an extreme insult because of my standards, ive had people do it to me claiming i had aimbot for bows but im just leading them (im better ranged then melee) but if your not hacking and this happens its one of or both reasons

1. Often they are just extremely salty they got killed which can be triggered by overconfidence or pride or
2. You can just be THAT good at pvp